Conventionally, amnions have been used in medical operations for reconstructing surfaces of eyes (see Non-patent Document 1), and frozen human amnions, which are used for reconstructing surfaces of eyes, have been known (see Non-patent Document 2).
Corneal stem cells are seeded and cultured on amnions so as to produce corneal endothelium-like sheets, which are used for implanting corneal endothelium (see Patent Document 1).
Further, Patent Document 2 discloses a dried amnion including no epithelial layer, which is produced by removing an epithelial layer of an amnion except a part of a basement membrane and dehydrating by a vacuum-freeze drying method, the dried amnion can be stored in a container without contacting oxygen, and the dried amnion can be used for curing a corneal disease after soaking the dried amnion into a buffer solution, etc. so as to rehydrate it.
Non-patent Document 1: Curr. Opin. Ophthalmol., 2001; 12: 269-281
Non-patent Document 2: Graefe's Arch. Clin. Exp. Ophthalmol., 2000; 238: 68-75
Patent Document 1: Japanese Patent Kokai Gazette No. 2004-24852
Patent Document 2: WO2004/078225